Question: Rewrite ${((6^{8})(7^{4}))^{-9}}$ in the form ${6^n \times 7^m}$.
Answer: ${ ((6^{8})(7^{4}))^{-9} = (6^{(8)(-9)})(7^{(4)(-9)})} $ ${\hphantom{ ((6^{8})(7^{4}))^{-9}} = 6^{-72} \times 7^{-36}} $